Wind tunnel tests reveal aerodynamics of dinosaurs

By Tereza Pultarova

Published Wednesday, September 18, 2013

British researchers have studied aerodynamic performance of feathered dinosaurs using equipment designed to tune aircraft.

Using a full-scale, anatomically correct model of a microraptor – the first theropod known to have feathers on its arms, legs and tail – scientists from the University of Southampton have tried to gain more insight into the evolution of bird flight.

They discovered that the four-wing configuration of microraptors allowed the animals to glide, generating a lot of lift with their four feathered limbs and a tail, representing the first stage in the evolution of two-winged flying creatures.

Flight simulations revealed the microraptors were able to glide slowly from trees and other low-elevation points, crossing considerably long distances with minimal height loss.

"Significant to the evolution of flight, we show that microraptor did not require a sophisticated, 'modern' wing morphology to undertake effective glides, as the high-lift coefficient regime is less dependent upon detail of wing morphology," said Gareth Dyke, senior lecturer in Vertebrate Palaeontology at the University of Southampton, explaining why the position and orientation of microraptor’s legs and wing shape showed to have little effect on dinosaur's flight.

"This is consistent with the fossil record, and also with the hypothesis that symmetric 'flight' feathers first evolved in dinosaurs for non-aerodynamic functions, later being adapted to form aerodynamically capable surfaces," he said.

The researchers believe they work has shed more light on how the first dinosaurs learned to fly.

"What interests me is that aerodynamic efficiency is not the dominant factor in determining Microraptor's glide efficiency. However, it needs a combination of a high lift coefficient and aerodynamic efficiency to perform at its best," said Roeland de Kat, Research Fellow in the Aerodynamics and Flight Mechanics Research Group at the University of Southampton.

The paper 'Aerodynamic performance of the feathered dinosaur Microraptor and the evolution of feathered flight' has been published in the latest issue of Nature Communications.